Technical Debt Prioritization: State of the Art. A Systematic Literature Review

Background. Software companies need to manage and refactor Technical Debt issues. Therefore, it is necessary to understand if and when refactoring Technical Debt should be prioritized with respect to developing features or fixing bugs. Objective. The goal of this study is to investigate the existing body of knowledge in software engineering to understand what Technical Debt prioritization approaches have been proposed in research and industry. Method. We conducted a Systematic Literature Review among 384 unique papers published until 2018, following a consolidated methodology applied in Software Engineering. We included 38 primary studies. Results. Different approaches have been proposed for Technical Debt prioritization, all having different goals and optimizing on different criteria. The proposed measures capture only a small part of the plethora of factors used to prioritize Technical Debt qualitatively in practice. We report an impact map of such factors. However, there is a lack of empirical and validated set of tools. Conclusion. We observed that technical Debt prioritization research is preliminary and there is no consensus on what are the important factors and how to measure them. Consequently, we cannot consider current research conclusive and in this paper, we outline different directions for necessary future investigations

Structural tailoring of engine blades (STAEBL)

A mathematical optimization procedure was developed for the structural tailoring of engine blades and was used to structurally tailor two engine fan blades constructed of composite materials without midspan shrouds. The first was a solid blade made from superhybrid composites, and the second was a hollow blade with metal matrix composite inlays. Three major computerized functions were needed to complete the procedure: approximate analysis with the established input variables, optimization of an objective function, and refined analysis for design verification

Concept definition study for recovery of tumbling satellites. Volume 1: Executive summary, study results

The first assessment is made of the design requirements and conceptual definition of a front end kit to be transported on the currently defined Orbital Maneuvering Vehicle (OMV) and the Space Transportation System Shuttle Orbiter, to conduct remote, teleoperated recovery of disabled and noncontrollable, tumbling satellites. Previous studies did not quantify the dynamic characteristics of a tumbling satellite, nor did they appear to address the full spectrum of Tumbling Satellite Recovery systems requirements. Both of these aspects are investigated with useful results

Space Trajectory Error Analysis Program (STEAP) for halo orbit missions. Volume 2: Programmer's manual

The six month effort was responsible for the development, test, conversion, and documentation of computer software for the mission analysis of missions to halo orbits about libration points in the earth-sun system. The software consisting of two programs called NOMNAL and ERRAN is part of the Space Trajectories Error Analysis Programs. The program NOMNAL targets a transfer trajectory from earth on a given launch date to a specified halo orbit on a required arrival date. Either impulsive or finite thrust insertion maneuvers into halo orbit are permitted by the program. The transfer trajectory is consistent with a realistic launch profile input by the user. The second program ERRAN conducts error analyses of the targeted transfer trajectory. Measurements including range, doppler, star-planet angles, and apparent planet diameter are processed in a Kalman-Schmidt filter to determine the trajectory knowledge uncertainty

Technology needs assessment of an atmospheric observation system for tropospheric research missions, part 1

The technology advancements needed to implement the atmospheric observation satellite systems for air quality research were identified. Tropospheric measurements are considered. The measurements and sensors are based on a model of knowledge objectives in atmospheric science. A set of potential missions and attendant spacecraft and sensors is postulated. The results show that the predominant technology needs will be in passive and active sensors for accurate and frequent global measurements of trace gas concentration profiles

Feasibility study of an Integrated Program for Aerospace vehicle Design (IPAD). Volume 1B: Concise review

Reports on the design process, support of the design process, IPAD System design catalog of IPAD technical program elements, IPAD System development and operation, and IPAD benefits and impact are concisely reviewed. The approach used to define the design is described. Major activities performed during the product development cycle are identified. The computer system requirements necessary to support the design process are given as computational requirements of the host system, technical program elements and system features. The IPAD computer system design is presented as concepts, a functional description and an organizational diagram of its major components. The cost and schedules and a three phase plan for IPAD implementation are presented. The benefits and impact of IPAD technology are discussed

Comparing text-based and dependence-based approaches for determining the origins of bugs

Identifying bug origins – the point where erroneous code was introduced – is crucial for many software engineering activities, from identifying process weaknesses to gathering data to support bug detection tools. Unfortunately, this information is not usually recorded when fixing bugs, and recovering it later is challenging. Recently, the text approach and the dependence approach have been developed to tackle this problem. Respectively, they examine textual and dependence-related changes that occurred prior to a bug fix. However, only limited evaluation has been carried out, partially because of a lack of available implementations and of datasets linking bugs to origins. To address this, origins of 174 bugs in three projects were manually identified and compared to a simulation of the approaches. Both approaches were partially successful across a variety of bugs – achieving 29–79% precision and 40–70% recall. Results suggested the precise definition of program dependence could affect performance, as could whether the approaches identified a single or multiple origins. Some potential improvements are explored in detail and identify pragmatic strategies for combining techniques along with simple modifications. Even after adopting these improvements, there remain many challenges: large commits, unrelated changes and long periods between origins and fixes all reduce effectiveness

Liquid Rocket Engine Turbopump Rotating-shaft Seals

A monograph is organized and presents, for effective use in design, the significant experience and knowledge accumulated in development and operational programs to date. It reviews and assesses current practices, and from them establishes firm guidance for achieving greater consistency in design, increased reliability in the end product, and greater efficiency in the design effort. The monograph is divided into two major sections: state of the art and design criteria

The Correlational Study of the Quality of Students Enrolled in the University and Employability of Graduates from Selected Universities in South-Western Uganda

The employability of university graduates is a concern for higher education stakeholders globally and Uganda is also concerned due to high unemployment rates post-graduation. Not much has been written about the relationship between quality of students enrolled in the university and their employability of graduates from selected Universities in South Western Uganda. This study aims to establish this relationship in selected universities in south western Uganda. A correlational study collected data from 512 participants, including graduates, employers, university lecturers, administrators, and officers from quality assurance directorate of national council for Higher Education. Data on students discipline, grades, performance and employability were collected.  SPSS and Structural equation modelling (SEM) version 21 was used to analyse associations between predictor and outcome variables. The findings derived from conducting this research clearly demonstrate the presence of a significant statistical association between the quality of students enrolled in the university and employability of graduates at R= 0.589, R squared change 0.347, P =0.000 This suggests that by ensuring the quality of students enrolled in the University through discipline, students’ grades and performance increases the likelihood of producing graduates who are employable.  It is very important that stakeholders in higher education make it a priority to keep a high standard of students and their moral fibre and this may facilitate their integration into the workforce